#include <config.h>
#include <version.h>
+#include <asm/global_data.h>
+#include <asm/processor-flags.h>
.section .text
.type _start, @function
.globl _i386boot_start
_i386boot_start:
+ /*
+ * This is the fail safe 32-bit bootstrap entry point. The
+ * following code is not executed from a cold-reset (actually, a
+ * lot of it is, but from real-mode after cold reset. It is
+ * repeated here to put the board into a state as close to cold
+ * reset as necessary)
+ */
+ cli
+ cld
+
+ /* Turn of cache (this might require a 486-class CPU) */
+ movl %cr0, %eax
+ orl $(X86_CR0_NW | X86_CR0_CD), %eax
+ movl %eax, %cr0
+ wbinvd
+
+ /* Tell 32-bit code it is being entered from an in-RAM copy */
+ movw $GD_FLG_WARM_BOOT, %bx
_start:
- movl $0x18,%eax /* Load our segement registes, the
+ /* This is the 32-bit cold-reset entry point */
+
+ movl $0x18, %eax /* Load our segement registes, the
* gdt have already been loaded by start16.S */
- movw %ax,%fs
- movw %ax,%ds
- movw %ax,%gs
- movw %ax,%es
- movw %ax,%ss
+ movw %ax, %fs
+ movw %ax, %ds
+ movw %ax, %gs
+ movw %ax, %es
+ movw %ax, %ss
- /* We call a few functions in the board support package
- * since we have no stack yet we'll have to use %ebp
- * to store the return address */
+ /* Clear the interupt vectors */
+ lidt blank_idt_ptr
/* Early platform init (setup gpio, etc ) */
- mov $early_board_init_ret, %ebp
jmp early_board_init
+.globl early_board_init_ret
early_board_init_ret:
- /* The __port80 entry-point should be usabe by now */
- /* so we try to indicate progress */
- movw $0x01, %ax
- movl $.progress0, %ebp
- jmp show_boot_progress_asm
-.progress0:
-
- /* size memory */
- mov $mem_init_ret, %ebp
- jmp mem_init
-mem_init_ret:
-
- /* fetch memory size (into %eax) */
- mov $get_mem_size_ret, %ebp
- jmp get_mem_size
-get_mem_size_ret:
-
- /* Check we have enough memory for stack */
- movl $CONFIG_SYS_STACK_SIZE, %ecx
- cmpl %ecx, %eax
- jae mem_ok
-
- /* indicate (lack of) progress */
- movw $0x81, %ax
- movl $.progress0a, %ebp
- jmp show_boot_progress_asm
-.progress0a:
- jmp die
-mem_ok:
- /* Set stack pointer to upper memory limit*/
- movl %eax, %esp
-
- /* indicate progress */
- movw $0x02, %ax
- movl $.progress1, %ebp
- jmp show_boot_progress_asm
-.progress1:
-
- /* Test the stack */
- pushl $0
- popl %eax
- cmpl $0, %eax
- jne no_stack
- push $0x55aa55aa
- popl %ebx
- cmpl $0x55aa55aa, %ebx
- je stack_ok
-
-no_stack:
- /* indicate (lack of) progress */
- movw $0x82, %ax
- movl $.progress1a, %ebp
- jmp show_boot_progress_asm
-.progress1a:
- jmp die
+ /* Initialise Cache-As-RAM */
+ jmp car_init
+.globl car_init_ret
+car_init_ret:
+ /*
+ * We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
+ * or fully initialised SDRAM - we really don't care which)
+ * starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
+ */
+ movl $CONFIG_SYS_INIT_SP_ADDR, %esp
+ movl $CONFIG_SYS_INIT_GD_ADDR, %ebp
+
+ /* Set Boot Flags in Global Data */
+ movl %ebx, (GD_FLAGS * 4)(%ebp)
+
+ /* Determine our load offset (and put in Global Data) */
+ call 1f
+1: popl %ecx
+ subl $1b, %ecx
+ movl %ecx, (GD_LOAD_OFF * 4)(%ebp)
+
+ /* Set parameter to board_init_f() to boot flags */
+ movl (GD_FLAGS * 4)(%ebp), %eax
-
-stack_ok:
- /* indicate progress */
- movw $0x03, %ax
- movl $.progress2, %ebp
- jmp show_boot_progress_asm
-.progress2:
-
- wbinvd
-
- /* Get upper memory limit */
- movl %esp, %ecx
- subl $CONFIG_SYS_STACK_SIZE, %ecx
-
- /* Create a Stack Frame */
- pushl %ebp
- movl %esp, %ebp
-
- /* stack_limit parameter */
- pushl %ecx
call board_init_f /* Enter, U-boot! */
/* indicate (lack of) progress */
movw $0x85, %ax
- movl $.progress4a, %ebp
- jmp show_boot_progress_asm
-.progress4a:
+ jmp die
+
+.globl relocate_code
+.type relocate_code, @function
+relocate_code:
+ /*
+ * SDRAM has been initialised, U-Boot code has been copied into
+ * RAM, BSS has been cleared and relocation adjustments have been
+ * made. It is now time to jump into the in-RAM copy of U-Boot
+ *
+ * %eax = Address of top of stack
+ * %edx = Address of Global Data
+ * %ecx = Base address of in-RAM copy of U-Boot
+ */
+
+ /* Setup stack in RAM */
+ movl %eax, %esp
+
+ /* Setup call address of in-RAM copy of board_init_r() */
+ movl $board_init_r, %ebp
+ addl (GD_RELOC_OFF * 4)(%edx), %ebp
+
+ /* Setup parameters to board_init_r() */
+ movl %edx, %eax
+ movl %ecx, %edx
+
+ /* Jump to in-RAM copy of board_init_r() */
+ call *%ebp
die: hlt
jmp die
hlt
+
+blank_idt_ptr:
+ .word 0 /* limit */
+ .long 0 /* base */
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